From 8f0667551329ec79f6547838269d2b53b9c0562b Mon Sep 17 00:00:00 2001 From: Andreas Baumann Date: Wed, 3 May 2023 20:01:59 +0200 Subject: updated IMC-2001 status --- content/hardware/imc-2001.md | 21 ++++++++++++++++++--- 1 file changed, 18 insertions(+), 3 deletions(-) (limited to 'content') diff --git a/content/hardware/imc-2001.md b/content/hardware/imc-2001.md index 7444f6e..1060f1b 100644 --- a/content/hardware/imc-2001.md +++ b/content/hardware/imc-2001.md @@ -13,12 +13,18 @@ Trying to fix several issues: - ROM 1 with BASIC is broken (and gets really hot). This explains the booting issues.. (will be tricky to get a replacement). The board layout doesn't fit to the original ROM sizes too.. -- the floppy driver read floppies (both) but both don't write to floppies +- the floppy drives read floppies (both) but they don't write to floppies (when copying in CP/M or creating a file), they work when formatting - a drive. Could be a side-effect of the PSU not working properly. + a drive on CP/M though. ~~Could be a side-effect of the PSU not working properly.~~ + The PSU has been replaced, the voltages look ok, so I rule out the PSU. + Could be some missing code in the Apple ROM (but that would be weird to + call 6502 firmware code from the Z80 CPU). It could also be the write + current being to low for writting (but why does formatting a drive work then?!) - the lever moving the contacts between 40-character and 80-character mode for the CRT output is corroded, doesn't always make contact and produces a flickering image +- the CRT is producing some flickering when turning the brightness nob, + this should be fixable with some deoxit. - keyboard cable is broken, at least the data line - the paddle and the joystick connectors miss some legs for putting them into the sockets on the motherboard @@ -26,11 +32,14 @@ Trying to fix several issues: Fixed issues: +- Reseated and deoxied all ICs, some of them were quite corroded, at + least 3 more turned out to be bad. Sadly it didn't have an effect on + ROM 1 not getting hot (must be something else). - ~~power switch made some hissing noises, it was not the switch, now the original power is dead (and some transformers are humming). Ordered a Apple 2 replacement PSU, waiting for it..~~ The new replacement power supply works like a charm, also replaced - the switch, as it was also unreliable + the power switch, the old one was too unreliable. - ~~sometimes I get into the monitor~~ - ~~lower-nibble bit 3 of the key being pressed is missing, unclear where it is lost, I suspect a @@ -56,6 +65,7 @@ Known things to work: as the keyboard works and the CP/M on the 80-character card I can also assume the Z80 is working just fine. - the 80-columns card (a Videx Videoterm or rather a clone of it) works just fine. +- the highres graphic mode works just fine, I can run "Peter Anvin Chess" and play it. # Images @@ -106,6 +116,11 @@ This is the "Operation Manual for IMC-2001, version 2.01": [The complete scanned manual](/hardware/imc-2001/manual_imc_2001_2.01.pdf) (also on archive.org, see [https://archive.org/details/manual_imc_2001_2.01](https://archive.org/details/manual_imc_2001_2.01)) +# Super Serial Card + +I got a super serial card from Ebay, the documentation of it can be +found here [https://archive.org/details/Apple_II_Super_Serial_Card_1981_Apple](https://archive.org/details/Apple_II_Super_Serial_Card_1981_Apple). + # Schematics Power connector on the motherboard: -- cgit v1.2.3-54-g00ecf